Thread: pgsql-server: Arrange for hash join to skip scanning the outer relation

Log Message:
-----------
Arrange for hash join to skip scanning the outer relation if it detects
that the inner one is completely empty.  Per recent discussion.  Also some
cosmetic cleanups in nearby code.

Modified Files:
--------------
    pgsql-server/src/backend/executor:
        nodeHash.c (r1.86 -> r1.87)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/executor/nodeHash.c.diff?r1=1.86&r2=1.87)
        nodeHashjoin.c (r1.65 -> r1.66)

(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/executor/nodeHashjoin.c.diff?r1=1.65&r2=1.66)
    pgsql-server/src/include/executor:
        hashjoin.h (r1.32 -> r1.33)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/executor/hashjoin.h.diff?r1=1.32&r2=1.33)